DOCSLIB.ORG

Radiation Degradation and Stability of Polymer

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Radiation Degradation and Stability of Polymer AASCIT Journal of Materials 2015; 1(2): 42-50 Published online July 20, 2015 (http://www.aascit.org/journal/materials) Radiation Degradation and Stability of Polymer Wangtong He, Xuejia Ding Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing, China Email address [email protected] (Xuejia Ding) Citation Wangtong He, Xuejia Ding. Radiation Degradation and Stability of Polymer. AASCIT Journal of Materials. Vol. 1, No. 2, 2015, pp. 42-50. Keywords Abstract Radiation Resistant Polymer In recent years, because of the advantage of radiation technology-low energy, clean, Materials, environmental protection, etc., so that the use of radiation technology for polymer Plasticizer, synthesis or processing research continues to heat up; however polymer materials Stabilizers, irradiated via high-energy radiation prone to produce free group or to react with atomic Antioxidants, oxygen in the air, resulting in the material cracking, crosslinking, branch, etc., it affects the Ligh Stabilizers, performance of the materials. In this paper, we focus on the need for the research of Hindered Amine Light Stabilizer radiation resistance of polymer material, It highlights the basic mechanism of polymer materials irradiation discoloration and the formulation of radiation resistant materials, which includes plasticizers, stabilizers, antioxidants and light stabilizers, the most representative is the study of a hindered amine light stabilizer and the latest irradiated Received: June 16, 2015 materials research. Revised: June 24, 2015 Accepted: June 25, 2015 1. Introduction It is well-known that the century of polymer materials paly a huge role. As polymer materials are widely used in medical and space technology, the development of research on radiation resistance of common polymer materials and space high-energy radiation and radiation resistance of high performance polymer materials gradually give rise to the attention of the countries all over the world. However, the vast majority of polymeric materials will change color-yellow, brown or black after undergoing high energy ray irradiation. In its radiation curing and radiation crosslinking process, due to the existence of radiation-induced discoloration affected its in processing performance (such as irradiation disinfection and sterilization) in many applications. Whereas radiation-induced changes in mechanical properties (and the chemistry which underlies these changes) have been extensively studied during the past four decades, radiation-induced changes in optical absorption have received little attention until quite recently and consequently this area has not been well explored. [1] Until recently, people realize the question for a more comprehensive and systematic exploration and research on the problem. 2. The Mechanism of Irradiation Discoloration The radiation degradation of polymer is the fracture of the main chain 、the lower molecular weight under the action of ionizing radiation, which turns out the solubility of polymer increase in the solvent, the corresponding the thermal stability and mechnical performance decrease. Because of the series of results producing by radiation degradation, so for the study of radiation degradation is far less attention than radiation crosslinking. In the process of polymer radiation degradation, the Oxidative degradation reaction will occur. 43 Wangtong He and Xuejia Ding: Radiation Degradation and Stability of Polymer 2.1. Radiation Degradation of Oxidation antioxidants of inhibition radiation oxidative degradation 、all Reaction kinds of light stabilizer and so on. Polymer irradiation discoloration whose products mainly 2.2. The Methods Irradiation Resistant include water, CO and CO 2 gas, alcohol, ketone, carboxylic acid and peroxide is the result of a series of reactions. For most We have already understood the mechanism of irradiation of the polymer, It is thought to be caused by radiation energy discoloration, based on the mechanism of it, we have a lot of automatic oxidation process, the process is as follows: research methods to prevent the color change of the polymer Initiation Reaction of Chain: materials.There is no doubt that the problem of the study will be very difficult, but I think that the study of this problem will RH→RH·→R·+H· have great significance. It will be further deepen for antioxidant, heat stabilizer and light stabilizers research. R·+O →ROO· 2 Radiation-resistant polymer materials will better applied to Propagation Reaction of Chain: humans. ROOH→RO·+HO· 3. The Basic Formula of Polymer ROOH→R·+HOO· Materials HO·+RH→R·+H O 2 3.1. Plasticizer ROO·+RH→ROOH+R· There is a large number of polar groups in the polymer RO·+RH→ROH+R· molecular and the intermolecular forces is strong. Not only making polymer processing performance deteriorate, but also Termination Reaction: causing polymer materials products stiffen, lacking of R·+R·→R-R elasticity and suppleness, which reflectes in physical and mechanical properties. There is some changes between the ROO·+R·→ROOR interaction force and the role of the intermolecular hydrogen bond force in polymer-plasticizer system after adding into a ROO·+ROO·→ROOR+O 2 certain amount of plasticizer. It makes polymer materials be easily processed and significantly increase of the elasticity and ROO·+RO·→ROR+O 2 flexibility in the products. That is to say, plasticizer is a Polymer materials fracture produce R· after high energy ray substance that adds into the material (usually plastic, resin or irradiation intermolecular; R· can react with oxygen to elastomer) to improve their processability 、flexibility and generate ROO· in the air; ROO· can also capture the hydrogen stretchability. Plasticizer can reduce system melt viscosity and atoms in polymer that produce ROOH and R·. From the above glass transition temperature and product elastic modulus, and chemical reaction equations, we can perceive that the will not change the basic chemical properties of the plasticized formation of R· is the direct cause of polymer materials materials. Polymer materials commonly used plasticizer is radiation photodegradation, Once produced alkyl oxygen free phthalate octyl lipid (DOP). Because of poisonousness of the radicals ROO·, it will take the hydrogen atoms of polymer DOP, there is some restrictions on the use of many countries. molecular chain to form the hydroperoxides. At room The current main non-toxic plasticizer have citric acid esters, temperature, hydrogen peroxide can be broken down slowly 1, 2-disubstituted cyclohexane dicarboxylic acid diisopropyl again to generate new free radical. there is no doubt that this ester type, Estman168 plasticizers, polyester plasticizer, will lead to further degradation of polymer materials. It is degradable biomaterials with plasticizer, epoxy plasticizer, simultaneity that chain rupture and crosslinking in the process etc. of polymer radiation degradation of oxidation. Chain fracture Citrate esters plasticizers are more easily moving out than make polymer relative molecular weight reduce while phthalate esters. It can be used in food packaging, medical brittleness reticular molecule generate by crosslinking, it leads appliances, children's toys and personal hygiene items, etc. 1, to the decreased of physical properties of the material. As a 2-disubstituted cyclohexane dicarboxylic acid diisopropyl result of the formation of the attraction of the conjugate group ester transparent and precipitate harderly, it has good and the fall of free radicals or ion make the polymer show the compatibility with polyvinyl chloride (PVC), so it can be used color change. Such as the macroscopic expression of for the preparation of transparent PVC. Eastman168 Polypropylene materials is yellow after high energy ray plasticizer which developed by the United States is a kind of irradiation. On this basis, we can improve the performance of environment-friendly plasticizers, it is characterized by the irradiation discoloration by enhancing the light stability of the security of higher and not cause harmful to human body. material performance: strengthen the shielding and absorption Polyester plasticizer is one main type of polymeric plasticizer, of radiation ray; reinforce the free radicals decomposition of it has the feature of the relatively high molecular weight and hydrogen peroxide; quench excited state molecules; capture can not easily move out, it can be used in high temperature free radicals. In other words, we can add plasticizer 、 AASCIT Journal of Materials 2015; 1(2): 42-50 44 insulation materials. Biodegradable plasticizer uses in materials like PVC by adding suitable amount of stabilizers, biodegradable materials, such as polylactic acid (PLA), it can which eliminates the materials that all had catalytic activity reduce itself hardness. Epoxy plasticizer is compounds for the thermal degradation reaction of chain (hydrogen containing three of epoxy group, it is the widely application of chloride and conjugated polyene).There are some kinds of plasticizer. More representative of the plasticizers is epoxy lead salt, metal soap, organic stannum, rare earth and soybean oil, which has good compatibility with PVC, the compound stabilizer we used commonly. advantage of it is high temperature resistant, and can not easily The type of lead salt stabilizer mainly refers to the basicity moved out, it also can make the active chlorine atoms of PVC of lead the inorganic and organic acids, such as three basicity chain more stability, and absorbe quickly
Load more

Recommended publications
  • Study of Polystyrene Degradation Using Continuous Distribution Kinetics in a Bubbling Reactor
    Korean J. Chem. Eng., 19(2), 239-245 (2002) Study of Polystyrene Degradation Using Continuous Distribution Kinetics in a Bubbling Reactor Wang Seog Cha†, Sang Bum Kim* and Benjamin J. McCoy** School of Civil and Environmental Engineering, Kunsan National University, Kunsan 573-701, Korea *Department of Chemical Engineering, Korea University, Seoul 136-701, Korea **Department of Chemical Engineering and Material Science, University of California, Davis, CA 95616, USA (Received 3 April 2001 • accepted 10 September 2001) Abstract−A bubbling reactor for pyrolysis of a polystyrene melt stirred by bubbles of flowing nitrogen gas at at- mospheric pressure permits uniform-temperature distribution. Sweep-gas experiments at temperatures 340-370 oC allowed pyrolysis products to be collected separately as reactor residue(solidified polystyrene melt), condensed vapor, and uncondensed gas products. Molecular-weight distributions (MWDs) were determined by gel permeation chro- matography that indicated random and chain scission. The mathematical model accounts for the mass transfer of vaporized products from the polymer melt to gas bubbles. The driving force for mass transfer is the interphase differ- ence of MWDs based on equilibrium at the vapor-liquid interface. The activation energy and pre-exponential of chain scission were determined to be 49 kcal/mol and 8.94×1013 s−1, respectively. Key words: Pyrolysis, Molecular-Weight-Distribution, Random Scission, Chain-end Scission, Continuous Distribution Theory INTRODUCTION Westerout et al. proposed a random-chain dissociation (RCD) model, based on evaporation of depolymerization products less than Fundamental and practical studies of plastics processing, such a certain chain length. In a subsequent paper [Westerout et al., 1997b] as energy recovery (production of fuel) and tertiary recycle (recov- on screen-heater pyrolysis, the RCD model was further described.
    [Show full text]
  • Pathways for Degradation of Plastic Polymers Floating in the Marine Environment
    Environmental Science Processes & Impacts View Article Online CRITICAL REVIEW View Journal | View Issue Pathways for degradation of plastic polymers floating in the marine environment Cite this: Environ. Sci.: Processes Impacts ,2015,17,1513 Berit Gewert, Merle M. Plassmann and Matthew MacLeod* Each year vast amounts of plastic are produced worldwide. When released to the environment, plastics accumulate, and plastic debris in the world's oceans is of particular environmental concern. More than 60% of all floating debris in the oceans is plastic and amounts are increasing each year. Plastic polymers in the marine environment are exposed to sunlight, oxidants and physical stress, and over time they weather and degrade. The degradation processes and products must be understood to detect and evaluate potential environmental hazards. Some attention has been drawn to additives and persistent organic pollutants that sorb to the plastic surface, but so far the chemicals generated by degradation of the plastic polymers themselves have not been well studied from an environmental perspective. In this paper we review available information about the degradation pathways and chemicals that are formed by degradation of the six plastic types that are most widely used in Europe. We extrapolate that information Creative Commons Attribution 3.0 Unported Licence. to likely pathways and possible degradation products under environmental conditions found on the oceans' surface. The potential degradation pathways and products depend on the polymer type. UV-radiation and oxygen are the most important factors that initiate degradation of polymers with a carbon–carbon backbone, leading to chain scission. Smaller polymer fragments formed by chain scission are more susceptible to biodegradation and therefore abiotic degradation is expected to Received 30th April 2015 precede biodegradation.
    [Show full text]
  • Biodeterioration of Untreated Polypropylene Microplastic Particles by Antarctic Bacteria
    polymers Article Biodeterioration of Untreated Polypropylene Microplastic Particles by Antarctic Bacteria Syahir Habib 1, Anastasia Iruthayam 1, Mohd Yunus Abd Shukor 1 , Siti Aisyah Alias 2,3 , Jerzy Smykla 4 and Nur Adeela Yasid 1,* 1 Department of Biochemistry, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia; [email protected] (S.H.); [email protected] (A.I.); [email protected] (M.Y.A.S.) 2 Institute of Ocean and Earth Sciences, C308 Institute of Postgraduate Studies, University of Malaya, Kuala Lumpur 50603, Malaysia; [email protected] 3 National Antarctic Research Centre, B303 Level 3, Block B, IPS Building, Universiti Malaya, Kuala Lumpur 50603, Malaysia 4 Institute of Nature Conservation, Polish Academy of Sciences, Mickiewicza, 33, 31-120 Kraków, Poland; [email protected] * Correspondence: [email protected]; Tel.: +60-(0)3-9769-8297 Received: 7 September 2020; Accepted: 22 October 2020; Published: 6 November 2020 Abstract: Microplastic pollution is globally recognised as a serious environmental threat due to its ubiquitous presence related primarily to improper dumping of plastic wastes. While most studies have focused on microplastic contamination in the marine ecosystem, microplastic pollution in the soil environment is generally little understood and often overlooked. The presence of microplastics affects the soil ecosystem by disrupting the soil fertility and quality, degrading the food web, and subsequently influencing both food security and human health. This study evaluates the growth and biodegradation potential of the Antarctic soil bacteria Pseudomonas sp. ADL15 and Rhodococcus sp. ADL36 on the polypropylene (PP) microplastics in Bushnell Haas (BH) medium for 40 days.
    [Show full text]
  • Determination of Polymer Stabilizers
    FLUORESCENCE APPLICATIONS ANALYSIS OF POLYMER STABILIZERS BY FLUORESCENCE SPECTROSCOPY USING THE MODEL LS-50 WITH THE FRONT SURFACE ACCESSORY ABSTRACT Quantitative analysis of a polymer UV stabilizer has been carried out using the PerkinElmer Model LS-50 Luminescence Spectrometer (L225-0105) fitted with the front surface accessory (5212-3130). The relationship between fluorescence emission and stabilizer concentration was found to be linear over the range observed for both native and extruded polymer samples. INTRODUCTION Many polymers such as polypropylene, polyethylene and polyvinyl chloride contain stabilizers to increase resistance to ultraviolet light-induced degradation. These additives can be relatively expensive, and the concentration required for effective UV stabilization can be quite critical. It is therefore desirable to monitor the concentration of the stabilizer in the parent polymer rather than relying on the calculation of the stabilizer dosing concentration based on the concentrations of the starting materials. This method allows for checking of homogeneity as well as the absolute concentration of the stabilizer. METHOD Polymer samples were supplied as native and extruded clear sheets. These were cut into 4 cm square sections and inserted into the front surface accessory using a piece of non-fluorescent card to keep the samples flat against the accessory window. Concentration of stabilizer was given as 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 mole %. RESULTS Data was collected as emission spectra, 390 nm - 550 nm, excitation wavelength 370 nm, slits 10/10 nm, scan speed 120 nm/min. The built-in emission attenuator (4 %T) was selected to decrease the assay sensitivity, as the samples were initially too strong for the extremely sensitive LS-50.
    [Show full text]
  • An Analysis of the Mechanisms and Efficacy of Three Liquid Chemical Soil Stabilizers
    Technical Report Documentation Page 1. Report No. 1993-1 2. Government 3. Recipient’s Catalog No. FHWA/TX-03/1993-1 (Volume 1) Accession No. 4. Title and Subtitle 5. Report Date AN ANALYSIS OF THE MECHANISMS AND EFFICACY May 2003 OF THREE LIQUID CHEMICAL SOIL STABILIZERS: VOLUME 1 7. Author(s) 6. Performing Organization Code Alan F. Rauch, Lynn E. Katz, and Howard M. Liljestrand 8. Performing Organization Report No. 1993-1 9. Performing Organization Name and Address 10. Work Unit No. (TRAIS) Center for Transportation Research The University of Texas at Austin 11. Contract or Grant No. 3208 Red River, Suite 200 Research Project 7-1993 Austin, TX 78705-2650 12. Sponsoring Agency Name and Address 13. Type of Report and Period Covered Texas Department of Transportation Research Report Research and Technology Implementation Office 14. Sponsoring Agency Code P.O. Box 5080 Austin, TX 78763-5080 15. Supplementary Notes Project conducted in cooperation with the Texas Department of Transportation and the U.S. Department of Transportation, Federal Highway Administration. 16. Abstract Liquid chemical products are marketed by a number of companies for stabilizing pavement base and subgrade soils. If effective, these products could be used as alternatives for treating sulfate-rich soils, which are susceptible to excessive heaving when treated with traditional, calcium-based stabilizers like lime, cement, and fly ash. However, the chemical composition, stabilizing mechanisms, and performance of these liquid products are not well understood. The primary objective of this study was to investigate and identify the mechanisms by which clay soils are modified or altered by these liquid chemical agents.
    [Show full text]
  • Additives for Polyolefins: Getting the Most out of Polypropylene
    ADDITIVES FOR POLYOLEFINS PLASTICS DESIGN LIBRARY (PDL) PDL HANDBOOK SERIES Series Editor: Sina Ebnesajjad, PhD ([email protected]) President, FluoroConsultants Group, LLC Chadds Ford, PA, USA www.FluoroConsultants.com The PDL Handbook Series is aimed at a wide range of engineers and other professionals working in the plastics indus- try, and related sectors using plastics and adhesives. PDL is a series of data books, reference works, and practical guides covering plastics engineering, applications, proces- sing, and manufacturing, and applied aspects of polymer science, elastomers, and adhesives. Recent titles in the series Biopolymers: Processing and Products, Michael Niaounakis (ISBN: 9780323266987) Biopolymers: Reuse, Recycling, and Disposal, Michael Niaounakis (ISBN: 9781455731459) Carbon Nanotube Reinforced Composites, Marcio Loos (ISBN: 9781455731954) Extrusion, 2e, John Wagner and Eldridge Mount (ISBN: 9781437734812) Fluoroplastics, Volume 1, 2e, Sina Ebnesajjad (ISBN: 9781455731992) Handbook of Biopolymers and Biodegradable Plastics, Sina Ebnesajjad (ISBN: 9781455728343) Handbook of Molded Part Shrinkage and Warpage, Jerry Fischer (ISBN: 9781455725977) Handbook of Polymer Applications in Medicine and Medical Devices, Kayvon Modjarrad and Sina Ebnesajjad (ISBN: 9780323228053) Handbook of Thermoplastic Elastomers, Jiri G. Drobny (ISBN: 9780323221368) Handbook of Thermoset Plastics, 2e, Hanna Dodiuk and Sidney Goodman (ISBN: 9781455731077) High Performance Polymers, 2e, Johannes Karl Fink (ISBN: 9780323312226) Introduction
    [Show full text]
  • Degradation and Recyclability of Poly (Ethylene Terephthalate)
    Chapter 4 Degradation and Recyclability of Poly (Ethylene Terephthalate) S. Venkatachalam, Shilpa G. Nayak, Jayprakash V. Labde, Prashant R. Gharal, Krishna Rao and Anil K. Kelkar Additional information is available at the end of the chapter http://dx.doi.org/10.5772/48612 1. Introduction The physical and chemical properties of polymers depend on the nature, arrangement of chemical groups of their composition and the magnitude of intra or intermolecular forces i.e primary and secondary valence bonds present in the polymer. Degradation process occurs due to the influence of thermal, chemical, mechanical, radiative and biochemical factors occurring over a period of time resulting in deterioration of mechanical properties and colour of polymers. The degradation occurs due to changes accompanying with the main backbone or side groups of the polymer. Degradation is a chemical process which affects not only the chemical composition of the polymer but also the physical parameters such as colour of the polymer, chain conformation, molecular weight, molecular weight distribution, crystallinity, chain flexibility, cross-linking and branching. The nature of weak links and end groups in the polymers contribute to stability of polymers. The degradation process is initiated at the terminal units with subsequent depolymerization. For example paraformaldehyde with hydroxyl terminal starts to degrade at about 170°C whereas the same polymer with acetyl terminals decomposes at about 200°C [1]. Replacement of carbon main chain with hetero atoms like P, N, B increases the thermal stability e.g. PON polymers containing phosphorus, oxygen, nitrogen and silicon. The exposure of polymeric materials to environmental factors over a period of time will lead to deterioration of physical, chemical, thermal and electrical properties.
    [Show full text]
  • Effect of Polymer Degradation on Polymer Flooding in Heterogeneous Reservoirs
    polymers Article Effect of Polymer Degradation on Polymer Flooding in Heterogeneous Reservoirs Xiankang Xin 1 ID , Gaoming Yu 2,*, Zhangxin Chen 1,3, Keliu Wu 3 ID , Xiaohu Dong 1 and Zhouyuan Zhu 1 ID 1 College of Petroleum Engineering, China University of Petroleum, Beijing 102249, China; [email protected] (X.X.); [email protected] (Z.C.); [email protected] (X.D.); [email protected] (Z.Z.) 2 College of Petroleum Engineering, Yangtze University, Wuhan 430100, China 3 Department of Chemical and Petroleum Engineering, University of Calgary, Calgary, AB T2N 1N4, Canada; [email protected] * Correspondence: [email protected]; Tel.: +86-27-6911-1069 Received: 3 July 2018; Accepted: 31 July 2018; Published: 2 August 2018 Abstract: Polymer degradation is critical for polymer flooding because it can significantly influence the viscosity of a polymer solution, which is a dominant property for polymer enhanced oil recovery (EOR). In this work, physical experiments and numerical simulations were both used to study partially hydrolyzed polyacrylamide (HPAM) degradation and its effect on polymer flooding in heterogeneous reservoirs. First, physical experiments were conducted to determine basic physicochemical properties of the polymer, including viscosity and degradation. Notably, a novel polymer dynamic degradation experiment was recommended in the evaluation process. Then, a new mathematical model was proposed and an in-house three-dimensional (3D) two-phase polymer flooding simulator was designed to examine both polymer static and dynamic degradation. The designed simulator was validated by comparison with the simulation results obtained from commercial software and the results from the polymer flooding experiments. This simulator further investigated and validated polymer degradation and its effect.
    [Show full text]
  • ASPHALTENE GRAFT COPOLYMER by FT-IR SPECTROSCOPY CT&F Ciencia, Tecnología Y Futuro, Vol
    CT&F Ciencia, Tecnología y Futuro ISSN: 0122-5383 [email protected] ECOPETROL S.A. Colombia León-Bermúdez, Adan-Yovani; Salazar, Ramiro SYNTHESIS AND CHARACTERIZATION OF THE POLYSTYRENE - ASPHALTENE GRAFT COPOLYMER BY FT-IR SPECTROSCOPY CT&F Ciencia, Tecnología y Futuro, vol. 3, núm. 4, diciembre, 2008, pp. 157-167 ECOPETROL S.A. Bucaramanga, Colombia Available in: http://www.redalyc.org/articulo.oa?id=46530410 How to cite Complete issue Scientific Information System More information about this article Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Journal's homepage in redalyc.org Non-profit academic project, developed under the open access initiative SYNTHESIS AND CHARACTERIZATION OF THE POLYSTYRENE - ASPHALTENE GRAFT COPOLYMER BY FT-IR SPECTROSCOPY Ciencia, Tecnología y Futuro SYNTHESIS AND CHARACTERIZATION OF THE POLYSTYRENE - ASPHALTENE GRAFT COPOLYMER BY FT-IR SPECTROSCOPY Adan-Yovani León-Bermúdez1* and Ramiro Salazar1 1Universidad Industrial de Santander (UIS) - Grupo de Polímeros, Bucaramanga, Santander, Colombia e-mail: [email protected] (Received April 30, 2008; Accepted Nov. 27, 2008) he creation of new polymer compounds to be added to asphalt has drawn considerable attention because these substances have succeeded in modifying the asphalt rheologic characteristics and physical properties Tfor the enhancement of its behavior during the time of use. This work explains the synthesis of a new graft copolymer based on an asphalt fraction called asphaltene, modified with maleic anhydride. Polystyrene functionali- zation is conducted in a parallel fashion in order to obtain polybenzylamine resin with an amine – NH2 free group, that reacts with the anhydride graft groups in the asphaltene, thus obtaining the new Polystyrene/Asphaltene graft copolymer.
    [Show full text]
  • Predictive Lifetime Models of Polymer Insulation Degradation and Biorenewable Thermosets Through Cati
    Iowa State University Capstones, Theses and Graduate Theses and Dissertations Dissertations 2013 Polymer damage mitigation--predictive lifetime models of polymer insulation degradation and biorenewable thermosets through cationic polymerization for self-healing applications Peter Raymond Hondred Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/etd Part of the Mechanics of Materials Commons Recommended Citation Hondred, Peter Raymond, "Polymer damage mitigation--predictive lifetime models of polymer insulation degradation and biorenewable thermosets through cationic polymerization for self-healing applications" (2013). Graduate Theses and Dissertations. 13105. https://lib.dr.iastate.edu/etd/13105 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Graduate Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. Polymer damage mitigation—predictive lifetime models of polymer insulation degradation and biorenewable thermosets through cationic polymerization for self- healing applications by Peter Raymond Hondred A dissertation submitted to the graduate faculty in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Major: Materials Science and Engineering Program of Study Committee: Michael R. Kessler, Major Professor Nicola
    [Show full text]
  • Properties of Poly(Vinyl Chloride) Modified by Cellulose
    Polymer Journal, Vol. 37, No. 5, pp. 340–349 (2005) Properties of Poly(vinyl chloride) Modified by Cellulose y Halina KACZMAREK, Krzysztof BAJER, and Andrzej PODGO´ RSKI Faculty of Chemistry, Nicolaus Copernicus University, Gagarin 7, 87-100 Torun´, Poland (Received July 30, 2004; Accepted February 9, 2005; Published May 15, 2005) ABSTRACT: Compositions of poly(vinyl chloride) with 2–10 (w/w) cellulose were prepared by extrusion. The mechanical properties and water absorptiveness of modified PVC have been measured. For the purpose of estimating the susceptibility to microorganisms’ attack, all samples were being composted in garden soil for up to 14 months. Mi- crobial analysis of soil used has been made. The biodegradation efficiency was estimated in terms and by means of weight loss, ATR-FT IR spectroscopy, as well as changes in mechanical resistance. Moreover, thermal stability of virgin and composted samples was studied by ther- mogravimetry. It has been found that the addition of a small amount of cellulose to PVC changes only slightly its properties. Inter- molecular interactions and also some thermal crosslinking taking place during the processing of samples’ preparation retard the biodegradation of PVC + cellulose blends. [DOI 10.1295/polymj.37.340] KEY WORDS Poly(vinyl chloride) / Cellulose / Blend Properties / Biodegradation / Thermal Stability / Polymeric materials have considerably influenced amounts (2–10 w/w) of cellulose, and to check the and enhanced the development of numerous branches susceptibility of samples to biodegradation. Accord- of industry owing to their various and diverse proper- ing to the published data,10 even a low content of nat- ties which can be additionally modified in a wide ural component in polymeric composition can induce range aimed at meeting the commercial and utility re- and facilitate its biodegradation.
    [Show full text]
  • Current Status of Methods Used in Degradation of Polymers: a Review
    MATEC Web of Conferences 144, 02023 (2018) https://doi.org/10.1051/matecconf/201814402023 RiMES 2017 Current Status of Methods Used In Degradation of Polymers: A Review Aishwarya Kulkarni1 and Harshini Dasari1 1Department of Chemical Engineering, Manipal Institute of Technology, Manipal, Manipal Academy of Higher Education, India. Abstract. Degradation of different polymers now a day is the most crucial thing to carry out. It possesses threats to human health as well as to the environment. Different polymers like PVA, PVC, and PP with high density and low density are one of the most consumed by population and also their degradation is a bit difficult. For this many people have started working on effective methods of degradation of these polymers. This can be done by thermal degradation and pyrolysis which requires high temperature, bio degradation using starch, bacteria etc and photo degradation. Traditional gravimetric and respirometric techniques are the methods currently used in testing. They fit readily for degradable polymeric materials usually. Also they are well suited for biodegradable components with polymer blends. But the recent polymer generation is comparatively resistant to bio degradation of polymers hence they cannot be used here. The polymer matrices are readily present in the plasticizers boosting the strength of polymeric material hence in addition; there is the mechanism of degradation. The information on various methods discussed in this review is planned to illustrate a best fit of methods for those who are interested in testing the degradation of polymers under different environmental conditions and selection of appropriate technique for specific combination of mixture of polymer and catalysts which helps to degrade the polymeric material.
    [Show full text]